Electric alarm-lock.



No. 739,272. PATENTED SEPT. 15, 1903'.

' 0. B. P. HIMMIGHOBFBR.

ELECTRIC ALARM LOOK.

APPLICATION FILED FEB. 9. 1903.

K0 MODEL.

W/7'NESSES:

A TTOR/VE) Patented September 15, 1903.

OTTO E. F. IIIMMIGHOEFER, OF ST. LOUIS, MISSOURI.

ELECTRIC ALARM-LOCK.

SPECIFICATION formingpart of Letters Patent No; 739,272, dated September 15, 1963.

Application filed February 9,1903. Serial No. 142,615 (No model.)

To all whom, it 711,607 concern:

Be it known that I, Orro E. F. HIMMIG- HOEFER, a citizen of the United States, residing at St. Louis, State of Missouri, have invented certain new and useful Improvements in Electric Alarm-Locks, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part hereof.

My invention has relation to improvements in electric alarm-locks; and it consists in the novel arrangement and combination of parts more fully set forth in the specification and pointed out in the claims.

In the drawings, Figure 1 is a plan of the interior of an ordinary door-lock, showing my invention applied thereto, both bolts being in their locking posit-ion. Fig. 2 is a similar view showing the door-knob bolt in its partially-retracted position, and Fig. 3 is a transverse section on line 3 3 of Fig. 1.

The object of my invention is to provide the ordinary door-lock with suitable electric connections whereby upon either the turning of the door-knob or the turning of the key an electric circuit will be closed, the closing of such circuit operating an alarm-bell, which may be located in any convenient part of the house, thereby giving notice of any attempt by unauthorized'persons to enter the house.

In detail the invention may be described as follows Referring to the drawings, 0 represents the casing of an ordinary lock, B the bolt operated by the turning of the knob K, and B the bolt operated by the turning of the key.

Projecting from the rear wall of the casing C are two binding-posts 1 1, from which lead wires to w, respectively, to a battery E and an alarm-bell A. The post 1 is carried dirictly by an insulating-plug 2. To the inner end of the post 1 is secured a circuit-closing spring or contact -strip 3, having an outwardly deflected or bent terminal 3 and an intermediate elbow 3, the key 4: being adapted to turn between these points and, irrespective of its position, force one or the other of the parts 3 3 against the bolt B or the metallic casing C, Fig. 2, by which action the circuit is immediately closed and the alarm sounded. So, too, by turning the knob in a direction to retract the bolt 13 the latter is brought in contact with the adjacent extension of the spring 3, thus again closing the circuit and with the same results. Normally, Fig. 1, the spring 3 is out of contact with any portion of the casing and of course the cir cuit is open.

It will be observed that with my present invention the burglar may even employ a key made of insulating or non-conducting material, the closing of the circuit being accomplished the moment an attempt is made to turn the key.

I do not, of course, wish to be limited to the details here shown, as these may in a measure be departed from without in any wise affecting the nature or spirit of my invention.

Having described my invention, what I claim is a 1. In a lock, acasing, a knob-actuated bolt, a key-actuated bolt, conducting-wires leading to the casing, a battery and an alarm in the circuit of the wires, and a contact-strip or spring having one end adapted to be forced against the key-actuated bolt or casing, and Y the opposite end adapted to be brought in contact with the knob-actuated bolt, substantially as set forth.

2. In a look, a metallic casing, a knob-actuated bolt, akey-actuated bolt, conductingwires, a battery and an alarm in the circuit of the wires, binding-posts carried by the casing and coupled to the wires, an insulating-plug for one of the posts, a contact-strip or spring coupled to the last-mentioned post, one end of the strip having an outwardlydeflected terminal and an intermediate elbow adapted respectively upon the turning of the key in proper direction to contact with the key-operated bolt or with the casing, the opposite end of the spring being adapted to contact with the adjacent end'of the knobactuated bolt, the parts operating substantially as and for the purpose set forth.

3. In an electric alarm-lock, a contact-strip In testimony whereof I affix my signature or spring having one end adapted to be actuin presence of two witnesses.

ated by the key and forced into contact there- Q by with the bolt, or wall of the casing, and OTTO HIMMIGHOEFER' 5 having the opposite end adapted to contact Witnesses:

with the knob-actuated bolt, substantially as l EMIL STAREK,

set forth.

G. L. BELFRY. 

